To convert inaccessible EDB files from Exchange Server to accessible NSF files including all items like notes, tasks, appointment, sent items and other related items go through SysInfo EDB to NSF Converter which can also fix all kinds of Exchange corruption problems like power fluctuation, server crash issues, virus attacks etc. So you can use this tool which can easily convert entire EDB file data to PST without loosing any single piece of information.
Download free version of this tool, here:- http://www.nsfsecurityremover.com/edb-to-nsf.html